Diagnostic and predictive accuracy of the Clinical Frailty Scale among hospitalised older medical patients: a systematic review and meta-analysis protocol

Introduction Frailty is a common condition affecting older adults and is associated with increased mortality and adverse outcomes. Identification of older adults at risk of adverse outcomes is central to subsequent resource planning and targeted interventions. This systematic review and meta-analysis will examine the: (1) diagnostic accuracy of the Clinical Frailty Scale (CFS) in identifying hospitalised adults >= 65 years with frailty and a medical diagnosis compared with the reference standard Frailty Index or Frailty Phenotype and (2) predictive value of the CFS in determining those at increased risk of subsequent adverse outcomes. Methods and analysis We will include cross-sectional, retrospective and prospective cohort studies, and randomised controlled trials that assess either the diagnostic accuracy of the CFS when compared with the reference standard Frailty Index/Frailty Phenotype or the predictive validity of the CFS to predict subsequent adverse outcomes in hospitalised adults over 65 years with medical complaints. Adverse outcomes include falls, functional decline, unplanned Emergency Department attendance, emergency rehospitalisation, nursing home admission or death. A systematic search will be conducted in Embase, AMED, MEDLINE (Ebsco, Ovid, Pubmed), CINAHL, PsycINFO, Cochrane Library. Studies will be limited to those published from 2005 to 30 October 2019. Two independent reviewers will screen all titles and abstracts to identify relevant studies. The methodological quality of studies will be independently assessed using the Quality Assessment of Diagnostic Accuracy Studies-2. A CFS score of >4 will be used to identify frailty. We will construct 2x2 tables and determine true positives, true negatives, false positives and false negatives for each study when compared with the reference standard and for each adverse outcome. A bivariate random effects model will be applied to generate pooled summary estimates of sensitivity and specificity. Ethics and dissemination Ethical approval is not required for this systematic review. We will disseminate our findings through a peer-reviewed journal.